EP0478181A1

EP0478181A1 - Seed peeling apparatus

Info

Publication number: EP0478181A1
Application number: EP91308333A
Authority: EP
Inventors: Toshiyuki Iizuka
Original assignee: INTER TEC ENGINEERING CO LTD
Current assignee: INTER TEC ENGINEERING CO LTD
Priority date: 1990-09-25
Filing date: 1991-09-12
Publication date: 1992-04-01
Also published as: US5181457A; CA2051532A1

Abstract

By rotating seed agitating means (18, 50, 80) such as a rotary cutter means (40) within a seed container (6, 22, 70) in which seeds such as of spinach and lawn grass are admitted, the seeds are peeled to separate seed cores from seed coats while being stirred. The seed cores free from the seed coats are allowed to pass through screen means (24, 58, 73) attached to the bottom of the seed container so as to collect stripped seeds thus obtained. The stripped seeds enjoys a very high rate of germination.

Description

This invention relates to a seed peeling apparatus for automatically removing seed coats from seeds such as of spinach and lawn grass or cracking the seed coats to increase the germinating rate of the seeds.
In general, a seed of an angiosperm such as spinach is composed of a relatively hard seed coat (exocarp) of about 2 to 4 mm in outer diameter and a seed core (stripped seed; endocarp) of about 1 to 3 mm in diameter which is enclosed in the seed coat. Though the seed coat has a function of protecting the seed core, it tends to hinder the germination of the seeds. Accordingly, when the seeds are sown as they are coated with the seed coats, the germinating rate of the seeds becomes remarkably low.
For instance, the Korean lawn grass native to China and the Korean Peninsula is broadly planted in a golf course because it is tolerant of blight and noxious insects. However, the seeds of lawn grass, when being coated with the seed coats, is low in germinating rate, i.e. about 15% at the most. Then, as one possible way for increasing the germinating rate of the seeds of the lawn grass, attempts are now being made to remove the seed coats from the seeds by hand before being sown. In this case, the germinating rate of the stripped seeds without seed coats could be improved, whereas the work of peeling off the seed coats from the seeds would be onerous and irrational.
In order to effectively peel the seeds, there has been used a pressure roller-type seed peeling apparatus in which the seeds are passed through between rotating rollers coming into pressure contact with each other so as to crush the seed coats. This apparatus however has entailed a disadvantage in that the seed cores enclosed in the seed coats were often damaged. In a case of peeling the seeds with fibrous or sticky seed coats, the seeds must be cooled to make the seed coats brittle. However, the problem in that the seed cores are damaged as stated above still remains. Therefore, with the conventional pressure roller-type seed peeling apparatus, the germinating rate of the seeds could not be increased over 30%. Moreover, the apparatus of this type is quite bulky and expensive.
However, the stripped seed which is obtained by completely removing the seed coat therefrom entails a problem such as deterioration to considerably shorten the life of the seeds. Therefore, the seeds have been desired to be preserved without deterioration for a long time.
This invention is made to eliminate the drawbacks suffered by the conventional seed peels apparatus as described above and has an object to provide a simple and convenient seed peeling apparatus for automatically removing seed coats from seeds with high efficiency without inflicting injury to the seed cores too much so as to increase the germinating rate of the seeds.
Another object of this invention is to provide a seed peeling apparatus capable of effectively cracking the seed coats by rotating cutting blades and automatically separating the seed cores from the seed coats by use of difference in mass between the seed core and seed coat.
Still another object of this invention is to provide a seed peeling apparatus capable of obtaining seeds which can be preserved without deterioration for a long time.
To attain the objects described above according to this invention there is provided a seed peeling apparatus comprising a container for seeds, seed agitating means rotatable within the seed container, and screen means attached to the bottom of the seed container.
The seed agitating means may be comprised of rotary cutter means with cutting blades. The cutting blades of the rotary cutter means are rotated to repeatedly give blows to the seeds in the seed container while stirring the seeds in all directions, consequently to cause the seed coats of the seeds to be broken or cracked.
A relief preventing means within the seed container is disposed for preventing the seeds in the container from rising when being stirred by the cutting blades. The efficiencies of peeling and stirring the seeds can be heightened.
Beneath the screen means attached to the bottom of the seed container, there may be provided a collecting receptacle for receiving the seed cores separated from the seed coats.
Upon putting the seeds into the seed container, the cutting blades of the cutter means are rotated to give blows to the seeds over and over while stirring the seeds in the container. As a result, the seed coats are broken and separated from the seed cores in time. When stirring the seeds, abrasive materials may be added into the container so as to effectively remove the seed coats broken or cracked from the seed cores.
Since the seed core is larger in mass than the seed coat, the seed cores free from the seed coats would subside and the waste seed coats separated from the seed cores come up in the seed container. The seed cores moving down to the bottom of the container would pass downward through the screen means into the collecting receptacle. The waste seed coats may be drawn out of the container through a suction pipe connected to a suction means such as a vacuum pump.
Otherwise, a rotary abrasive member for shaving the seeds may be used as the aforenoted seed agitating means, so as to make the seed coats sufficiently thin. The seeds with thin seed coats would germinate readily, thereby remarkably increasing the germinating rate of the seeds. Also in this case, abrasive materials may be added into the container to effectively shave the seeds.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein Figure 1 is a sectional side elevation schematically showing a first embodiment of a seed peeling apparatus according to this invention; Figure 2 is an exploded perspective view of the seed peeling apparatus of Figure 1; Figure 3 is an exploded perspective view of a rotary cutter means in the seed peeling apparatus of Figure 1; Figure 4 is a plan view of the rotary cutter means of Figure 3; Figure 5 is an explanatory diagram showing the state of stirring and peeling seeds in the seed peeling apparatus of this invention; Figures 6(A) and 6(B) are explanatory diagrams showing a the state of peeling a seed in the seed peeling apparatus of this invention; Figure 7 is a sectional side view schematically showing the principal portion of a second embodiment of the invention; Figure 8 is a sectional side view schematically showing a third embodiment; and Figure 9 is a schematic view showing a seed peeling system in a fourth embodiment of the invention.
The seed peeling apparatus shown in Figures 1 and 2 as a first embodiment of the present invention comprises a base member 4 having leveling means 4a, a supporting upright column 8 fixed on the base member 4, a bracket 10 disposed movably vertically along the upright column 8, a substantially cylindrical seed container 6 for seeds S which is supported by the base member 4, and a seed agitating means 12 which is held by the bracket 10.
In this embodiment, the seed agitating means is a rotary cutter means for giving blows to and peeling the seeds in the seed container 6.
The rotary cutter means 12 comprises a rotary driving means 14 such as a motor which is retained by the bracket 10, a rotating shaft 16 connected to the rotary driving means 14 through a joint means 20, and a rotating blade means 18 attached to the lower end portion of the rotating shaft 16.
The seed container 6 comprises a container body 22 having a seed inlet opening 22a and a bottom opening 22b, screen means 24 covering the bottom opening 22b, and a collecting receptacle 26 attached to the lower side of the screen means 24. The seed inlet opening 22a of the seed container 22 may be covered with a lid member 28.
Inside the seed container 22, there is disposed a relief preventing means 30 for preventing the rising of the seeds S which is caused by stirring the seeds in the seed container 6 by the rotating blade means 18. Though the relief preventing means 30 comprises a retainer 36 extending downward from a stiffening rib 38 and a substantially cone-shaped keep plate 34 retained on the lower end of the retainer 36 as illustrated in the drawings, the structure of the relief preventing means 30 should not be understood as limited to the illustrated embodiment. An alternate structure for retaining the keep plate may be employed in which the keep plate 34 is supported by horizontal rods (not shown) extending radially inward from the inner surface of the container body 22.
The screen means 24 may be composed of a net or net-like plate with a mesh smaller than the average diameter of a stripped seed (seed core N) and larger than the average diameter of a seed S with seed coat.
As illustrated in Figure 3 and 4, the blade means 18 of the rotary cutter means 12 used as the seed agitating means in this embodiment comprises an upper blade 40, a lower blade 42 intersecting with the upper blade 40, and an auxiliary blade 44 extending curvedly downward from the blade 42. As a matter of course, the upper and lower blades 40 and 42 may be integrally formed in one body by, for example, stamping out a steel plate.
The upper blade 40 has a fixing flat portion 40a, an upward inclined portion 40b, and a downward inclined portion 40c. The upward and downward inclined portions 40b and 40c each have a cutting edge (40d or 40e). The cutting edges 40d and 40e are not very sharp and somewhat large in curvature so as not to cut the seed entirely. There has been actually manufactured an upper blade 40 of 2 mm in thickness (t1) at the fixing flat portion 40a and 0.08 mm in thickness (t2) at the free ends of the upward and downward inclined portions 40b and 40c. In this blade, the angles ϑ1 and ϑ2 of the upward and downward inclined portions 40b and 40c relative to the fixing flat portion 40a are about 15°, respectively.
The lower blade 42 has a fixing flat portion 42a and an obliquely rising portion 42b. Similarly to the cutting edges 40e of the upper blade 40, the obliquely rising portion 42b has a cutting edge 42c which is not very sharp and somewhat large in curvature so as not to cut the seed entirely. In the actually manufactured blade 42, the angle ϑ3 of the obliquely rising portion 42b relative to the fixing flat portion 42a is about 45°. The auxiliary blade 44 has also a cutting edge 44a.
One example of the fixing structure of the upper and lower blades 40 and 42 to the rotating shaft 16 is shown in Figure 3. This fixing structure is constituted by a non-circular projection 16a formed at the lower end of the rotating shaft 16, a non-circular holes 40d formed in the upper and lower blades 40 and 42, and a screw 46.
In Figures 1 and 2, reference numeral 48 denotes a suction pipe having a suction port positioned nearly at the level of the keep plate 34. The suction pipe 48 is connected to suction means 50 such as a vacuum pump.
Although the blades 40 and 42 and other elements have been described as one example, it is understood that these are not restrictive and may be embodied in several forms.
Now, the principle of peeling the seeds to separate the seed cores from the seed coats according to the seed peeling apparatus of this invention will be described with reference to Figure 5.
Upon putting the seeds S with the seed coats into the seed container 6, the cutter means 12 is driven to rotate the blade means 18 so as to give blows to the seeds with the rotating blades 40, 42 and 44 while stirring as indicated by the arrows in Figure 5. The seeds S which rise with the rotation of the blades would move upward along the lower surface of the conical keep plate 34 and converge to the apex of the keep plate 34. As a result, the seeds S would come under pressure between the blade means 18 and the conical keep plate 34 and be disabled from escaping. Therefore, the seeds under pressure would effectively suffer blows by rotating blades while being stirred up.
The seed coat H of the seed S in the container 6 is cracked by the rotating blades 42 as indicated by the mark CR in Figure 6(A) and repeatedly suffers blows. As a result, the seed core N goes out of the seed coat H as shown in Figure 6(B).
The seed core N larger in mass than the seed coat H would subside to the bottom of the container 6 and pass through the screen means 24 to the collecting receptacle 26. On the other hand, the seed coats H which are smaller in mass than the seed cores N come up and are drawn out through the suction pipe 48.
Where the cutter means 12 was experimentally rotated at 2400 rpm for about 30 minutes in the seeds of spinach put in the container according to this invention, the yield of seeds (ratio of the desired seed cores N to the untreated spinach's seeds S with seed coats) was about 25% on the average. In this experiment, the germinating rate of the stripped seeds was as high as about 80% on the average. The stripped seeds obtained according to this invention were subjected to a coating treatment with chemicals for temporary protection before being planted.
The result of the experiment on the effect of the damage rate of the stripped seeds (seed cores N) on germinating rate of the seeds proved that the seeds were apt to receive deadly injuries when the cutter means continued driving at 3000 rpm over about 15 minutes. Also, it was found that in the case of rotating the cutter means 12 at a low rate of speed of about 1220 rpm, the driving time of the cutter means should preferably be determined to 40 to 45 minutes. When the cutter means was driven at a high speed to crack the seeds in a short time and then gradually decelerated, the most adequate results were obtained.
Though the yield of the stripped seeds in one peeling operation was relatively low, it could however increase when the seeds were subjected several times to the peeling treatment with the apparatus of this invention.
Though only one unit of the seed peeling apparatus is used in the illustrated embodiment, a plurality of units may be interlinked so as to construct a seed peeling plant.
In a case of the Korean lawn grass, the germinating rate of the untreated seeds with seed coats is usually as low as about 15%, whereas the same could be remarkably increased to about 80% by utilization of the seed peeling apparatus of this invention.
The effect of peeling the seeds can be heightened by stirring the seeds together with abrasive materials in the container. In the experiment actually carried out, the yield of the stripped seeds (seed cores) relative to 500 grams of the seeds of Korean lawn grass was improved to 72% where 375 g of abrasive materials mainly containing silicon carbide was added to the seeds in the seed container 6 and the cutter means 12 was driven at 2400 rpm for 120 minutes. In place of silicon carbide, emery may be used the abrasive materials.
In the case of peeling the seeds of spinach by use of the abrasive materials, a desired ratio of the abrasive materials to the seeds is about 10 to 30 weight %. In the case of lawn grass, it is desirable to add the abrasive materials in the order of 5 to 40 weight % relative to the seeds.
The second embodiment of the seed peeling apparatus according to this invention is shown in Figure 7, in which a seed agitating means 50 has a rotary abrasive member 52. In this embodiment, abrasive materials m is put in a container 56 along with seeds S. The rotary abrasive member 52 for stirring the seeds S with the abrasive materials has a roughened surface curved slightly. By driving a rotating shaft 54 provided at its lower end with the rotary abrasive member 52, the seeds in the container 56 are abrasively contacted with the roughened surface of the abrasive member 52 and the abrasive materials m so as to effectively make the seed coats thin uniformly. The fact that the seed peeling apparatus 1 having only the abrasive member 52 could attain sufficiently high germinating rate of the seeds was experimentally confirmed.
The seed agitating means 50 is not limited merely to the rotary abrasive member 52. For example, an agitating flow of compressed air or otherwise possible agitating methods may be used as the seed agitating means.
The seeds which are shaved by the rotary abrasive member 52 while being agitated by the aforenoted agitating means 50 are separated into the seed cores N and seed coats H. The seed cores N being larger in mass than the seed coats would sink to the bottom of the container 56 and pass through screen means 58. The seed coats H being smaller in mass than the seed cores come up and are drawn out through a suction pipe 59.
The third embodiment shown in Figure 8 comprises a container 70 supported by a frame 62, a motor 64 mounted on the frame 62, a follower shaft 66 driven by the motor 64 through the medium of a belt 68, and a seed agitating means 80 attached to the lower end of the follower shaft 66. The seed agitating means 80 is composed of striking means similar to the cutting blades in the first embodiment shown in Figure 1.
The container 70 is composed of a container body 71 having a seed inlet opening 72, screen means 73 constituting the lower half portion of the container 70, and a collecting member 74. The screen means 73 has a cylindrical side portion 73a to allow the seed cores taken out from the seeds to pass therethrough effectively.
The collecting member 74 has a cylindrical side portion 74a surrounding the side portion 73a of the screen means 73 so as to form a space between the portions 73a and 74a.
The container 70 may preferably be provided with a peep hole 76 covered with a transparent reinforced plastic plate or the like to observe the interior of the container 70.
In the drawing, reference numeral 77 denotes an openable bottom plate, and 78 a seed-core collecting receptacle. The striking means 80 serving as the seed agitating means may be rotated at a high speed to break and remove the seed coats of the seeds S similarly to the first embodiment described above. However, it is sufficient to merely crack the seed coats of the seeds by causing the striking means 80 to be rotated at a low speed or driven for a short time.
The seed coat cracked permits penetration of water into the seed core, but still protects the seed core thereby preventing the seed core from being injured. As a result, the germinating rate of the seeds can be increased.
When stirring the seeds S in the container 70, the abrasive materials m may be added to promptly make the seed coats thin.
From the results of the experiments in which the seeds of lawn grass are stirred with the abrasion materials mainly containing silicon carbide, it was found that most suitable products can be obtained by rotating the striking means 80 at about 1300 rpm for about 90 minutes. In the experiments, the seed coats were shaved off by 5 to 10 weight %. If the seed coats are more reduced in thickness, the seed cores are susceptible to injury. If the seed coats are not shaved sufficiently, the germinating rate of the seeds is decreased. The seeds suitably shaved as noted above are easily cracked by rotating the striking means 80.
A system including the seed peeling apparatus of this invention as described above is illustrated in Figure 9. This seed peeling system comprises a collecting device 92 for collecting the seed cores falling on the collecting member 74 through the screen means 73 with suction force, and a seed discriminator 90 having a storage container 96 for indiscriminately sucking out through a suction means 94 and temporarily storing the seed cores, seed coats, and seeds with seed coats cracked, a separating device 97 for separating the seed cores and seeds with seed coats from the seed coats by utilization of mass differences among them, and a sieve device 98 for sieveing substances fed from the separating device 97 to completely remove the waste seed coats free from the seeds.
According to the seed peeling system described above, desired seed cores and seeds with cracked seed coats which exhibit high germinating rate can be readily mass produced automatically.
As will be apparent from the foregoing, according to the seed peeling apparatus of this invention, seeds of various sorts can be automatically peeled to remove the seed coats from the seed cores with high efficiency without inflicting injury to the seed cores too much. As a result, the germinating rate of the seeds can be increased remarkably. Besides, according to this invention, only the stripped seeds free from the sees coats can effectively be collected by utilization of difference in mass between the seed cores and seed coats. The convenient seed peeling apparatus according to this invention is simple in structure and can be manufactured at a low cost.

Claims

A seed peeling apparatus comprising a seed container (6, 22, 70) for seeds each consisting of a seed core coated with a seed coat, said container having a seed inlet opening (22a) and a bottom opening (22b), seed agitating means (18, 50, 80) rotatable in said seed container, and screen means (24, 58, 73) with a mesh smaller in diameter than the seed core and larger in diameter than the seed coat so as to permit the seed core to pass therethrough, said screen means being attached to said bottom opening of said container.
The apparatus according to claim 1, further comprising a collecting receptacle (26, 74) disposed under said screen means (24, 73).
The apparatus according to claim 1 or claim 2, further comprising a relief preventing means (30) having a substantially cone-shaped keep plate (34) disposed in said seed container.
The apparatus according to any of claims 1 to 3, further comprising a suction pipe (48, 59) connected to a suction means (50) for drawing out the seed coats separated from the seed cores.
The apparatus according to any of claims 1 to 4, wherein said seed container is supported by a supporter means composed of a base member (4) having a supporting column (8) on said base member a bracket (10) disposed movably vertically along said column and said seed agitating means (18) is held by said bracket.
The apparatus according to any of claims 1 to 5, wherein said seed agitating (18) means is a rotary cutter means (12) having cutting blades (40, 42) rotatable in said seed container.
The apparatus according to claim 6, wherein said cutter means (12) comprises upper and lower blades (40, 42) intersecting with each other, and an auxiliary blade (44) extending curvedly downward from said lower blade, said upper blade (40) having a fixing flat portion (40a), and upward and downward inclined portions (40b, 40c) each having a cutting edge (40d, 40e).
The apparatus according to any of claims 1 to 5, said seed agitating means (50) is composed of a rotary abrasive member (52) for stirring the seeds, said rotary abrasive member having a roughened surface curved slightly.
The apparatus according to any of claims 1 to 5, said seed agitating means (80) is a striking means (82) having a plurality of striking blades.
A seed peeling apparatus comprising a seed container (6, 22, 70) for seeds each consisting of a seed core coated with a seed coat, said container having a seed inlet opening (22a, 72) and a bottom opening (22b), seed agitating means (18, 50, 80) rotatable in said seed container, screen means (24, 58, 73) so as to permit the seed core to pass therethrough, said screen means being attached to said bottom opening of said container, a collecting member (26, 74) attached to the lower side of said screen means, a collecting device (92) for collecting the seed cores falling on the collecting member through the screen means with suction force, and a seed discriminator (90) having a storage container (96) for indiscriminately sucking out through a suction means (94) and temporarily storing the seed cores, seed coats, and seeds with seed coats cracked, a separating device (97) for separating the seed cores and seeds with seed coats from the seed coats by utilization of mass differences among them, and a sieve device (98) for sieveing substances fed from the separating device to completely remove the waste seed coats free from the seeds.